Airfix 1/24 Sea Harrier FRS1

[sohoppy]

As a 'work in progress', this is a bit of a fraud really as this very lengthy project is now finished. But I thought I'd share my working pictures in case the way I do these things is of any interest to anyone else.

 

My models tend to be 'museum type' i.e. little or no weathering. There are, in any case, many folks here on these pages who do that sort of thing much much better than I do. On the other hand my aircraft models feature most, or in this case all, of the following:

- Fully working flight controls, controlled by stick and rudder.

- Manually retractable undercarriage

- 'Pose-able' flaps

- Lighting -  nav, collision and cockpit

- Illuminated HUD or gunsight

- Working props, fan, turbines etc

 

This is the story of how I did these things with the Airfix Harrier. Quite the hardest plastic kit I've tackled - weeks of putty and scribing, rinse and repeat!

[bootneck]

Hello sohoppy,

I have that kit in the stash so I would like to see your working pictures please.

 

Mike

[bigbadbadge]

Me too although mine is started with the rivet detail now filled, sanded etc. Looking forward to some pics.

Chris

[sohoppy]

Hi there, no problem.

 

A quick bit of background. Why this kit? Well, I'm of an age that I remember them flying about, as I lived near Portsmouth as a child and my dad was ex Grey Funnel. Also I very much like the high viz scheme as it harked back to the heyday of the FAA in the 60's and 70's.

Also, when push came to shove in the Falklands, the Navy, as we know, found itself up against it with terrible weather, a much more numerous aerial foe and saddled with equipment that some thought not really up to the job at hand - including the 17 yr old me (like many teens, an expert at absolutely everything). But as so very often in the past, RN sailors and pilots proved, once again, it's not the kit that counts but who is actually in it. In any case, it turned out the air combat capability of the SHAR was not all that well understood, outside the small community that flew them and the US pilots they trained with.

So to business. I got myself the Flightpath 'detail up' set and some bits and pieces from Simian Stuff. To begin with, as everyone has reported before, one needs to get rid of the rivets. I tried perfect putty and wet sanding but this just lifted the putty out. Epoxy putty was too hard and only used around the intakes. This left Humbrol putty which more or less worked out.  Visting the FAA museum at Yeovil, you can see that the rivets are mostly (save access hatches) totally invisible.

 

I started with the cockpit as this is where all the control linkages emanate from. These were made from brass stock and essentially are a lot of bell cranks linked by push rods except for the aileron control which, as you may be able to make out, worked using crown gears to convert a side to side motion to fore and aft.

Edited March 25, 2022 by sohoppy

[wellsprop]

Fantastic! 

[sohoppy]

In this picture you can see the box type arranagement behind the instrument panel. This is to stop the panel lights from 'bleeding' out and I normally paint the interior white. I put tubes in the back which allow one to insert LEDs. Acess to the LEDs is via the radome.

 

 

For the brass push rods that have to go furthest - rudder and elevators - I put them in brass tubes to reduce the flex as they move.

 

 

The cockpit is a mix of Simian, Flightpath and kit parts. I probably should have done a better job on the throttle and exhaust angle levers...

 

What flightpath provided which was great for this project was a photoetch panel with some acetate dials one can illuminate form behind.

[sohoppy]

In this picture you can see the forward wheel well with the optic fibres that illuminate the wing lights snaking past. Behind it you can see the cranks that move aileron control aft over the motor. I cannot emphasise enough that in this type of scheme there can be no binding or fouling of the controls. The tiny range of motion - and the delicacy of the parts - mean you have to try, fit, try, fit until it works literally perfectly.

 

Annoyingly, despite the considerable size of the kit, all the controls have relatively restricted pathways as there are either gear doors or a turbine or other obstruction blocking most routes... Was quite a fiddle.

 

 

The wheel well is painted black because the forward gear will have a bright lamp on it and the paint reduces light bleed when the wheel is in the 'up' position.

 

 

Edited March 25, 2022 by sohoppy

[bigbadbadge]

Wowee, that is amazing work. 

Chris

[Farmerboy]

Stunning, can’t wait to see the finished article, don’t keep us waiting!

[NickD]

Hi Sohappy,

 

Love the ambition. Harrier is a fav of mine too.

 

"Annoyingly, despite the considerable size of the kit, all the controls have relatively restricted pathways as there are either gear doors or a turbine or other obstruction blocking most routes... Was quite a fiddle."

 

The control runs on the real thing were not much better judging from some of the pictures. 😀

 

Nick

 

[Alan P]

7 hours ago, sohoppy said:

My models tend to be 'museum type' i.e. little or no weathering. 

You had me at hello 😂

[Billy400]

More photo's please that's awesome. I especially like the way you are hand making functional flight controls.

[Tony C]

I've got a GR.3 on long term build, so I'll tag along as well, more than likely I'll learn something along the way

[sohoppy]

Many thanks for all the comments, and definitely more pictures on the way...

 

So, where were we? Generally after doing the flight controls, one has to move onto the wheels which present their own set of problems. First off, the wheels have to be firmly atached to the airframe and so cannot wait until the end of the project, as most modellers seem to do for ease of painting.

 

Also, these 'semi-mechanical' models are even heavier than the ordinary versions because of all the stuff in them, so the plastic kit wheels are never likely to be strong enough. Also, to look realistic, they need to contain springs strong enough to lift the aircraft to the right level on the oleos and yet be squishy enough to fit in the wheel wells, ususally at a full detente position.

 

On the Harrier, the nose gear is the challenge as this has a very snug fit in the well and will have to fit under pressure because any spring strong enough to lift the nose will thouroughly resist setting the gear to 'up'. Also the strut is a quite complex shape.

 

I made mine of soldered brass stock with pins for the moving joints that can be removed at any stage for dissassembly and a spring change. Then I hollowed out the plastic parts so the brass would work as a kind of insert.

 

 

 

Here you cans see the dollshouse wire I use for electric cabling and some of the Flightpath/Simian stuff being added

 

 

Adding to the complexity, the gear has two push rods that open the rear door that comes down with the gear. The length and design of these needs to be spot on so the door closes and opens flush with the two main doors. You'll see what I mean later on.

 

Meanwhile, further aft, we have the main gear which is simpler to make and has a really roomy well which is a real luxury. On my Tamiya F4J 'Silverkite 211', on these pages somewhere, the main wheel wells turned out to be too shallow - or the wheels too fat - to actually fit, resulting in a lot of extra work. Here no such issue.

 

In fact there was room enough for a lipo battery and a couple switches. You can also make out the rudder and horiz stab linkages on their way aft. To get the gear to lock down I attached a small but very strong neodymium magnet to the wheel strut that sticks to a corresponding one just inside the well. Since, on the Harrier conveniently, the doors are always shut, even in gear down position, this arrangement is quite invisible.

 

Edited March 26, 2022 by sohoppy

[sohoppy]

On closer examination my F4J was at LSP here https://forum.largescaleplanes.com/index.php?/topic/71983-tamiya-132-f-4j-silverkite-211-with-working-features/#comment-986351 back in 2017.

[bigbadbadge]

Looks excellent,  the front U/C legs is fantastic,  really looking forward to seeing all this together and in action.

Really great work 

Chris

[sohoppy]

Hello again,

This time, wings.

 

 

In the picture above, you can make out the control linkage to the bell crank which converts the fore-aft motion of the aileron linkage into side-to-side for the rods as they pass through the wing.  The control rod is square-section stock for much of its length to prevent buckling in compression. A lot of 'control authority' can be lost that way at this scale.

 

There are, of course, other ways of doing all this. My 1/24 Hurricane uses thread and pulleys, not unlike the real thing. And I used rotational control rods on my Phantom. But bell-cranks and push/pull rods, overall, provide the best range of mechanical movement, in my view. You can achieve all of this electrically too as RC modellers do all the time. But it's a fiddle at this scale.

 

Lower in the picture is the universal dog bone style joint which connects the two flaps.

 

You can also make out the small black screws I used to attach the wings to the fuselage. There is a convenient flange for doing this and it makes for a strong join which is helpful, again, to reduce unwanted flexing in the model, once assembled.

 

In the picture below you can see how the aileron rod joins another bell crank before connecting to the aileron itslef which is hinged at each end. The flaps and tail, by contrast have hinges embeded in the control surface itself, as per the real thing. The ailerons have tiny control 'horns' - hidden by the existing fairings underneath the wing - to provide enough mechanical advantage to move them.

 

 

You can see that, as usual I added a wing spar. This is becuase the model is heavy and there will be a load of sorts on the outrigger wheels.

 

But also, once the flight control system works, it is pretty vital that nothing shifts or warps when the aircraft parts are sealed up, to prevent moving parts fouling each other - when it far too late to anything about it! The spars stiffen things up appreciably. The brass is glued to the plastic with superglue and little pins made of 0.8mm brass wire which provides a surprisingly strong connection. These can be (carefully) filed smooth where they protrude the other side of the model parts.

 

The outrigger wheels were obviously not designed to move in the kit so I first had to figure out how the real ones actually did - and then try to replicate the motion. The wheels also have suspension in the form of springs within 'telescoping', square-section, brass rod. This stops the wheels from yawing. The final visble part of the oleo is brass rod that has been chromed with the very handy Caswell plating set from the US, which I use on pretty much every kit these days.

 

Up

 

and down

 

And here are the flap hinges in progress.

 

The hinge rods were glued to the styrene kit parts and then faired over with sections of evergreen tube, sliced in half. Cue yet more filler and sanding. When finished these required very careful fitting to the wing as they must be exactly half way up the wing's thickness and line up with the ailerons - and everything else.

 

And here it is altogether.

 

Thanks for looking!

 

 

[Stu123]

This is amazing work.  Watching this with interest!

[Paulaero]

OMG  and I thought putting flashing lights in was impressive, this is another level.....👏

[junglierating]

On 3/25/2022 at 9:04 PM, NickD said:

Hi Sohappy,

 

Love the ambition. Harrier is a fav of mine too.

 

"Annoyingly, despite the considerable size of the kit, all the controls have relatively restricted pathways as there are either gear doors or a turbine or other obstruction blocking most routes... Was quite a fiddle."

 

The control runs on the real thing were not much better judging from some of the pictures. 😀

 

Nick

 

You're not wrong blind wirelocking a specialty 😁

[bigbadbadge]

Wow, phenomenal stuff. Great work. 

Chris

[ColinChipmunkfan]

This is amazing modelling/engineering at the highest level. I am watching this with awe and admiration.

Colin

[Back in the Saddle]

Incredible work👍.

[sohoppy]

Hello all, and many thanks indeed for the kind comments - although I tend to associate 'model engineering' with something rather more precise and skilled - than what I've been doing here! I, personally, can't tell a Whitworth from a BA, or even how you work it out, sadly.

 

Anyhow, onwards and upwards. Today, tails.

 

The rudder is usually the simplest flight control to achieve. All you need to remember is which way it goes when you press the rudder pedals one way or another and fix your linkages accordingly. In this case, the hinges are slightly exposed so the other caution is to watch out for overspray when it comes to painting or it will all seize up. The turning moment on the little 'horn' is not great and it is very easily impeded.

 

The 'l' shaped piece with two holes in is to attach the lower end of the rudder actuator to the fuselage side to stop it moving in any but a rotational way.

 

 

I have tried before to do all flying tail fins with just simple brass bushings but this never seems to work and is always too stiff. So I ended up using, as with my Phantom before, a couple of very small, wheel-race bearings and the results were immediate and pleasing. Some, very careful(!), hollowing out of the kit plastic was required to get a proper non-binding fit at the base of the control rod.

 

Ignore the brass rod in the roller bearing, this is just waiting to engage in the tail plane actuator arm. You can also just about see the optic fibres for the tail nav lights. They are sheathed with wire insulation to stop the glow that you would see through the 'puffer' vents.

 

 

The tail planes are invariably not balanced in their original kit form which means that, if you fit them as is, they generally sag down and aft. For a model like this where everything is pretty delicate, that means the joy stick will be pulled aft and become hard to push forward which is less than ideal. So some way needs to be found to balance them around the fulcrum where they connect to the airframe and each other.

 

I don't know why I didn't think of this before but it ought to be possible to weight the tail parts internally with lead sheet before joining lower and upper halves together, which would be neat. I chose the much less elegant way of using a lead counterbalance which is also less than ideal because it also restricts the degree of available movement.

 

This is inelegant on many levels but it does work, with a bit of finessing. The brass strip pressing against the tail plane control rod is there to stop it pinging out. You can't take any chances as, if it pings when you close it up, well, then that's kind of it.

 

One last thing, the two tail planes need to be exactly parallel to each other, set at the correct anhedral and lock together when you push them into position. This, needless to say, must be sorted out before installation.

 

That's all for now. Some actual modelling stuff next time!

Edited March 31, 2022 by sohoppy
text error

[bigbadbadge]

Fantastic stuff, can't wait to see  all this in action .

Great work 

Chris